A colony of primates has been established and is being fed a diet rich in sucrose, all the components of which are normally purchased for human consumption. Many animals are developing carious lesions and it appears that animals vaccinated using polysaccharide antigens are not protected. The lymphocytes from all animals, even the infected nonvaccinated respond in vitro to 8 antigens derived from S. mutans. The development of simple, safe, effective vaccine against dental caries would be a significant public health measure. Results from a number of investigations indicate that rodents and primates can be protected to some extent against caries; however, the optimal route of administration, correct dose and most appropriate antigen remain to be identified.